Energy
Since the start of the Industrial Revolution in the 1760's human society has become increasingly dependent on energy. Many advances in technology were pushed forward in the quest for reliable and economical sources of power. Initially this power came from coal or wood fuelled steam engine and later from the burning of fossil fuels such as oil and gas to power turbines. In the mid-20th century nuclear fission became available but this never completely replaced fossile fuel. These sources were in turn supplemented by renewable and/or sustainable power source such as solar and wind power from the late 20th century. It was only in the 2040's, with the development of fusion power, that humanity was able to finally end it's reliance on Earths rapidly depleting fossil fuels. Fusion Power Early attempts at fusion power, in the 20th and early 21st century were generally not hugely successful. Early reactors could not sustain a prolonged reaction for very long, often just a few seconds. It was not until joint Sino-WEU CERN project of the 2040's that the first fully operational reactors were built. The early generation of fusion reactors were fairly large and cumbersome, although they were no where near as large as fission plants, and could only produce a maximum of between 16 and 20mW. Eventually the design was refined and improved and in 2058 the first 120mW reactor was unveiled at the Shanghai Technology Park. Within ten years both China and Western Europe (including the UK) had shut down all of their fossil fuel and fission power plants. At the same time both Russia and the USA were undertaking massive construction projects of their own. with the USA producing 40% of its energy needs through fusion by 2065. The availablility of cheap energy, combined with the development of high density batteries and ultra-effficient electric motors, meant that by the 2060's electric-powered vehicles were now cheaper to run than those utilising oil based fuels (gasoline/petrol and diesel) and the electric car soon outnumbered its conventional counterpart in many countries. This had the effect of reducing the economic power of the still oil rich countries of the Middle East, causing their economies to slowly but inevitably decline, leading eventually to the water crisis of 2115 and the subsequent nuclear exchange of World War Three. Today fusion power plants provide more than 80% of the energy needs of Earth and the major colonies, the rest coming from a variety of sources including fuel cells, solar, tidal and wind power as well as hydro-electric. Fuel Cells Fuel cell technology dates back to the 1830's making it even older than the internal combustion engine. The principle of fuel cells is incredibly simple, comprising of an anode (negitive side), a cathode (positive side) and an electrolyte which allows the charge to pass between the two sides. In many ways a fuel cell is like a battery, the difference been that they require a constant supply of both fuel (usually hydrogen) and an oxidiser. A hydrogen-oxygen fuel cell has no by-products except sterile water. The most common fuel source is hydrogen but other sources such as methanol or hydrocarbons can also be used although these are slightly less efficiency and create other by-products. For more infomation of the technology see here By the early 21st century fuel cells power plants were being used by increasing numbers of companies as independent power sources, freeing them from the rising costs of fossil fuel-sourced power companies. In 2026 the Tornoto Commonwealth Games were almost entirely powered by fuel cells, the remaining power needs coming from solar panels and wind turbines. The main stumbling block for truly wide scale fuel cell use was the cost of platinum which was is the best material for the catalyst. The discovery, in 2035, of several platinum rich asteroids helped lower the costs to the point where even small factories or isolated communities could afford to purchase fuel cells in the 150-200kW range. Other Sources Nearly ninety percent of the energy generated on Earth comes from either fusion power plants or fuel cells. Despite this there remains a thriving market for renewable and sustainable energy sources, particularly within countries with limited access to helium-3 reserves or those where the sheer size of the country limits the construction of a national grid. The main forms of this energy production are solar power, wind power, and hydro-electric (including tidal energy). Solar power comes in two main forms - photovoltaics and solar thermal energy. Photovoltaic, more commonly called solar panels or solar cells, directly convert light from the sun into electricity whilst solar thermal uses focusing mirrors to concentrate the heat of sunlight to super heat water into steam which turns a turbine. Today solar cells are rarely used for large scale commercial energy production. Those large arrays which do still exist are used to provide power locally rather than for national grids. Many homes and smaller commercial facilities do retain solar panels and in isolated "off-grid" locations solar is the prefered source of power (usually PV although Solar sterling engines are also popular). The main form of solar energy generation is solar thermal. Focused sunlight is used to heat up a medium, either mineral oil or blocks of graphite, which in turn heats water to generate steam which turns a turbine. The main problem with both forms of solar energy generation is that they require large areas of land in regions which experience high levels of sunlight. Available, affordable, land is often long distances from urban centres requiring the construction of a major infrastructure to carry the energy to where it is needed. Using wind turbines to generate electricty first became truly practical in the late 20th century and by 2050 nearly 2% of the worlds energy was generated by wind power either by large wind farms or by individual small scale turbines. Most of the worlds wind farms were (and remain) located off-shore where the wind remains fairly constant. Energy Storage The main problem with most secondary power sources is that they are intermittent, solar power is only available during daylight hours, wind turbines only operate when the wind is blowing above a certain speed, and hydro electric plants are dependent on a regular source of water. Solar and wind power can also be irregular meaning they may be capable of generating large amounts of power but the energy might not be needed at that time. The solution is energy storage. The three main methods of energy storage are - Pumped storage hydroelectric, compressed or liquid air storage, and liquid salt storage. A fourth method, large battery banks, is generally considered uneconomical on a large scale. The largest liquid air storage facility currently in service is the Sunking-A power station outside Pheonix, Arizona in the USA. Here five 1mW fuel cells are used to chill and compress air into a series of gigantic pipes buried beneath the desert. These four pipes are ten metres in diameter and over half a kilometre long, each pipe holds just over 155'000m³ metres of liquid air. When needed this air is passed through a heat exchanger which causes it to expand at great speed, the air then passes through a series of wind turbines. In total the plant can generate 50mW an hour for up to four hours. Plans are underway to expand Sunking-A with two more fuel cells and three more pipes. The land above the storage pipes is covered by a mixed solar Sterling/PV solar cell network which generates 8.5mW at peak, this energy feeds directly into the local grid. The CEGD is constructing an even larger air storage facility on the plains to the south of Ulan Bator. This plant will use a mix of fuel cells and wind turbines to fill pipes with a total capacity of over 220'000m³. These will supply turbines capable of generating a total of 60mW. High Density Batteries For smaller scale operations, including most domestic sites, batteries remain an economical and efficient method of energy storage. By far the most common form of batteries is the High Density (Hi-D) or 3D Electrode battery. First developed in 2013 by the University of Illinois Hi-D batteries can have more than twice the storage capacity of a Li-Ion or zinc-carbon battery of the same size and can be recharged hundred of thousands of time without major loss of capacity. As an example a commercial AA cell Hi-D battery, of the sort normally found in small flashlights, has a nominal voltage of 1.5V and a capacity of 2'100mAh at 500mA constant drainage. Two of these are sufficient to run a 4-LED, 25 lumens flashlight for up to five hours continuously. Most homes, small commercial premises, and most electric vehicles use larger multi-cell 12V batteries with capacities ranging from 2.5 to 11kWh. The largest producer of high density batteries is General Electric which manufactures over a million batteries a year. Category:Background